1CS372Introduction to Operating SystemsLorenzo AlvisiWeijiang YuDepartment of Computer SciencesThe University of Texas at [email protected]@cs.utexas.eduhttp://www.cs.utexas.edu/~lorenzo/corsi/cs372/03F/CS372.htm2Why Study Operating Systems?Not many Operating Systems (OS) under developmentIt is unlikely that I will build new OS in your job… So, why should I study operating systems?Because…ÿ OS is everywhere – it manages all computing resourcesÿ OS is a wizard – it provides to users an illusion of infinitememory, CPU, resourceÿ OS provides abstractions – it makes systems convenient to usev Tradeoffs between convenience, simplicity and performanceÿ OS provides services that enable application programsÿ OS is the point where hardware and software meetÿ … knowledge of how OS works makes you a more effectivecomputer user!!3CS372Capstone courseÿ Combines things from many different coursesv Programming languagesv Data structuresv Algorithmsv …Projectsÿ Build components of an operating systemv Thread/process manager, file system, transaction system, …ÿ Enhance software engineering skillsv Thread programming, build large systems, group projectsI hear and I forget; I see and I remember;I do and I understand !I hear and I forget; I see and I remember;I do and I understand !4Do I really want to do this?What will I learn?Learn how to write multi-threaded programsÿ Learn the fundamentals of management of concurrencyLearn how programs can execute in an environmentprotected from other programsÿ Memory managementÿ Processor schedulingLearn how files can be accessed seamlessly from anywhere inthe worldÿ Caching, file system design and content distribution…5Three-levels of LearningHow to approach problemsÿ Example: problem definition, design-space exploration, casestudiesÿ Goal: When faced with a similar problem, you should be able todevise a solutionÿ Timescale: big long-term payoffSpecific techniques and algorithmsÿ Example: concurrent programming, two-phase commit,transactions, …ÿ Goal: Be a good engineerÿ Timescale: immediately useful – but also useful in long-termDetails of modern OSÿ Examples: Linux, Windows, Solaris, BSD, Darwin…ÿ Problem: lots of material, changes quicklyÿ Not a priority for this course6AdministriviaTextbooksTextbook:ÿOperating System Concepts, 6th edition, by Silberschatz, Galvin& Gagne, Addison Wesley, 1998 (5th edition is ok too)Other useful books:ÿThe C++ Programming Language, 2nd edition, by BjarneStroustrup, Addison Wesley, 1991ÿOperating System Internals and Design Principles, WilliamStallingsÿ ..ÿ … and an assorted collection of C++ and Unix references7AdministriviaGrading PolicyExamsÿ Midterm (25%)ÿ Final examination (25%)Projects and programming assignments (50%)ÿ Tentative plan: 2 programming assignmentsNo homework (to be formally submitted)ÿ Practice problems and solutions will be postedÿ Plan to hold recitation sections to help you gain practice insolving problems8AdministriviaHomework and programming assignmentsProgramming assignments are due at the start of class onthe due dateÿ Anything handed in after I start lecturing is considered lateÿ Late submissions will not be acceptedGrading will focus on correctnessRequests for re-grade must be made within a week after youreceive your graded assignmentsProgramming assignments to be done in groups of two9AdministriviaCollaboration and CheatingWorking in groups on homeworks is OK but…ÿ You can only collaborate with other students in the courseÿ Every student must craft their own final solutionÿ Every student must fully write up their solutionÿ All collaborators must be acknowledged in writingCollaborationÿ Discuss problem sets and programming assignmentsÿ Discuss possible interpretation of questions, technical detailsCheatingÿ Copying solutions code or programs from someone else, previousyear’s solutions, or public domainÿ Participate in discussion group where one person writes solutionand everyone else copies it10AdministriviaHow to get an “A” in this courseAttend class regularlyÿ Ask questions!ÿ Take notesÿ Understand key conceptsRead the bookÿ Keep up with the lecturesDo the homework and programming assignmentsÿ Try problems on your ownStudy!11Assume getting copies of handouts is sufficientDon’t take notes in classMiss classesStart assignments at the last minuteÿ Assignments are designed to require several hours of workoutside of class each weekMemorize details without understanding conceptsAdministriviaHow to get an “D” in this course12AdministriviaWhere to go for help?Ask questions in class!ÿ Exercise your understanding of the course material on a daily basisAttend office hoursÿ Lorenzo’s office hours are T/TH 2:00 – 3:00PM in ACES 6.244ÿ Weijiang’s office hours: M: 2:00-3:3; W: 1-2:30 in ACES 5SEo3CDon’t send questions via e-mailÿ I want to get to know youÿ I don’t want to be subject to denial of service attacksYour primary avenue for resolving questions is office hoursÿ If you can’t come to office hours, setup an appointment13AdministriviaCourse Information and HandoutsSlides will be made availableUpdates will be available